Spring device



Feb. 13, 1962 .1. H. MAKER 3,021,129

SPRING DEVICE Original Filed Sept. 1, 1959 INVENTOR JAMEs H- MAKERATTORNEYS um/022w WW iiniteti 1 Claim. (Ci. 267-1) This application is adivision of my co-pending application Serial No. 837,512, filedSeptember 1, 1959 for Spring Device.

This invention relates to springs and spring devices and provides acompression spring device which produces substantially uniform loadingabout the circumference of its end convolutions and, most importantly,has a low rate throughout a considerable deflection. Although theinvention is not limited to springs of any particular size or range ofdiameters, it has been found to be of great utility in applicationrequiring springs of relatively large diameter and in which it isdesirable to maintain parallel end surfaces, a condition known assquareness under load, throughout a considerable range of deflections,

and in applications in which, because of their flexibility, the springstend to produce non-uniform loading about their end convolutions undervarying temperature conditions or over a range of deflections.

It is often necessary to provide a substantially uniform resilientpressure over an annular member subjected to wide variations intemperature with consequent expansion and contraction of the metalparts. In known devices for producing such resilient pressure in acircular pattern an annular series of a plurality of helical compressionsprings is used, the outer ends of which engage a fixed or adjustablemember. The springs of such an assembly are differentially responsive tovariations in temperature and the assembly therefore produces unevenpressuresabout the annular member. In addition, such an annular assemblyof a number of springs has marked disadvantages in cost, weight andspace. Such an annular assembly of springs also has a relatively highrate, which is an undesirable characteristic in many applications.Further, it is often necessary or desirable to have a close degree ofsquareness under load, which is not achieved by the .annular assembly ofsprings.

It is a particular object of this invention, therefore, to provide asingle spring device which will take the place of the annular series ofcompression springs heretofore used for the described and similarpurposes, which will exert substantially uniform pressure at all pointsabout the circumference of its end convolutions, which will have a lowrate of increase in load over a considerable range of deflection, andwhich will have a close degree of squareness under load.

The invention is described in the following specification and isillustrated in the accompanying drawing, in which:

FIG. 1 is a side View, partly in section and partly in elevation,showing a spring device according to the invention, assembled to asealing means;

FIG. 2 is a perspective view of a spring device ac cording to theinvention, and

FIG. 3 is a perspective view showing a second embodiment of theinvention.

In FIG. 1 of the drawings there is illustrated an assembly of partsincluding a spring device formed in accordance with this invention andproviding new and improved results. This assembly comprises a hollowvessel 2 into which the end of a pipe or shaft 4 extends. Au

3,Zl,l29 Patented Feb. 13, 1962 annular sealing member 6 surrounds thepipe or shaft and has one of its axial or end surfaces in face-to-faceengagement with an end surface of the vessel 2 audits other axial or endsurface spaced axially from a fixed abutment member 8. A compressionspring device 10,

which is constructed in accordance with this invention is disposedbetween and bears at its ends on the outer axial,

surface of the sealing member 6 and on the spaced surface of the fixedabutment 8 and surrounds the pipe or shaft 4. In present and knownpractice, in a typical assembly of this kind the part 4 is of largediameter, the sealing member 6, in accordance with known practice, isheld, against the vessel 2 by an annular series of small helicalcompression springs, and the entire assembly is heated in;

tion. These helical spring elements are arranged concentrically about acommon axis to form a cylindricalspring device and are equallycircumferentially spaced,

and wound in the same direction. The spring elements are connectedtogether at the inactive end of each element so that the active,helically shaped portions of the elements work in parallel and there isonly one inactive convolution at each end of the assembly. The elementsforming the spring device may be connected by welding, brazing,riveting, mechanical ties, or by any other suitable means.

One embodiment of the invention is-disclosed in FIG.

2 and comprises a three-element spring device consistingof the helicalelements 20, 22, 24 which have the same shape and are preferably equalin size in all dimensions.

Element 2% of this assembly has a flat, arcuate end part- 26 whichextends through one-third of the circumference of thespring device atone end thereof, a second or intermediate part 28 which is acontinuation of the fiat end part 26 and which is shaped as a helix, anda second end part 30 which is fiat and arcuate and extends throughout,one-third of the circumference of the spring device: at

the second end thereof. The second element 22 is connected at its oneend to the juncture of the flat part 26 and the intermediate part 28 ofthe element 20 and, extending from this end, has a fiat, arcuate part 32which forms an arcuate circular continuation of the flat part 26 ofelement 20 and extends through one-third of the circumference of thedevice, then a second or intermediate part 34 which is shaped as ahelix, and then a fiat, arcuate end part 36 which forms a circularcontinuation of the fiat, arcuate end part 30 of element 20 and whichextends throughout one-third of the circumference of the cylindricalassembly. The third element 24 is connected at its one end to thejuncture of the flat part 32 and the intermediate, helical part 34 ofelement 22 and, extending from this end, has a fiat, arcuate part 38which forms a circular continuation of the arcuate, fiat parts 26 and 32of elements 20 and 22, respectively, and which extends through one-thirdof the circumference of the cylindrical assembly to complete the fiatend member of the spring device at its one end. The third element 24also has a helical intermediate part 40 which forms a continuation ofthe flat end part 38, and a second fiat, arcuate end part 42, whichforms a continuation of the helical part 46 and which extends throughoutone-third of the circumference of. the cylindrical assembly at thesecond end of the spring device, thus completing the fiat end member atthat end. I

It will be seen that" the described spring device, in the embodiment nowbeing described, comprises the two circular, inactive end parts, oneconsisting of the flat, arcuate parts 26, 32, 38 of elements 23, 22, 24and the other consisting of the flat, arcnate, parts 34}, 36, 42 of thesame three elements. These flat, circular, inactive ends are connectedby the three helically shaped convolutions 23, 34, 4B which form part ofelements 28, 22, 24, respectively, and each of which extends from oneinactive end coil of the spring device to the other and also extendsthroughout one-third of, the circumference of the spring device, wherebyeach forms one-third of a full helical convolution. The helicallyshaped. parts act separately and in combination with each other toresist axial loads exerted. on the end members in approachingdirections, whereby the entire device, and each of the three elements,acts as a compression spring. Because of the equal spacing andarrangement of the three spring ele merits the loading on both ends ofthe spring will be equal throughout the entire circumference, thuscausing uniform loading. Thus, it will be seen in FIG. 1 thatthe flatend convolution of the spring device 10 will exert a uniform forcethroughout its circumference on the sealing member 6 regardless ofvariations in the temperatures to which the spring device is subjected,with consequent expansion or contraction of the parts, and regardless oivariations in the normally parallel relation of the sealing ring 6 andthe abutment 8. Further, the spring device 10 has a: very low rate evenunder considerable deflection, such as that produced by movement ofmember 8 toward sealing ring 6.

A spring device according to the invention may include any number ofhelical spring elements and in FIG. 3 of the drawings there is disclosedan embodiment of the invention which is similar in all respects to thatdisclosed in FIG. 2- except that it has only two elements forming thespring parts and the inactive end parts of the device, instead of thethree elements of the device of FIG. 2. Each of these two elements 59,52 has an arcuate, flat end part at each end of the spring device, eachof which parts extends throughout one-half of the circumference of thecylindrical device, and which end parts are connected by a helicalmember which may be of any arcuate length, i.e-., it may extend throughany angle, depending on the relativepositions of the ends of the arcuateend parts. Thus, in the embodiment of the invention disclosed in FIG. 3the element St has the two arcnate, flat end parts 54, 56, each ofwhichextends through 180 and which are connected by the helical part 58.The member 52 has the two arcuate, flat end parts 60, 62 connected bythe helical part 64. The two helical parts 58, 64 are of relativelyshort arcuate length in the embodiment illustrated in FIG. 4 because ofthe positioning of the ends of the tint end parts of the two memberswith respect to each other. The flat end parts 54, of the two membersare connected to form one circular end convolution of the spring deviceand at the other end of the device the two fiat parts56, 62 areconnected to form an annular, inactive end coil. The device disclosed inthis figure operates in exactly the same mannor as that'disclosed inF162.

While I have described and illustrated embodiments of the inventionhaving either two or three spring elements, devices having four or moreconvolutions may be used within the purview of the invention. More thanfour elements decrease the efiiciency of the device but might be used insome circumstances.

While I have described and illustrated several forms which my inventionmay take, it will be understood by those skilled in the art that otherembodiments, as well as modifications of those disclosed, may be madeand practiced without departing from the spirit or scope of theinvention, for the limits of which reference must be made to theappended claim;

What is claimed is:

A spring device comprising a plurality of integral spring elementsconnected to form a cylindrical spring device having an annular memberat each end thereof, each of said spring elements comprising a flatarcuate part at each end thereof and a helical part. connecting saidarcuate parts, the arcuate parts of said elements being connected ateach end of the spring device to provide the annular member at that endand the helical parts of said elements being arranged in spacedcircumferential relation to connect the annular end members of thespring.

device.

References Cited in the file of this patent UNITED STATES PATENTS

